Beverage container base



FIG. 1 is a front perspective view of a beverage container base showing my new design;

FIG. 2 is a rear perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a right side elevation view thereof, the left side elevation view being a mirror image thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines in all views are shown for environmental purposes only and form no part of the claimed design. 

The ornamental design for a beverage container base, as shown and described. 